/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.container.entrypoint;

import org.apache.flink.annotation.Internal;
import org.apache.flink.annotation.VisibleForTesting;
import org.apache.flink.api.common.JobID;
import org.apache.flink.client.deployment.application.ApplicationClusterEntryPoint;
import org.apache.flink.client.deployment.application.ClassPathPackagedProgramRetriever;
import org.apache.flink.client.program.PackagedProgram;
import org.apache.flink.client.program.PackagedProgramRetriever;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.PipelineOptionsInternal;
import org.apache.flink.runtime.entrypoint.ClusterEntrypoint;
import org.apache.flink.runtime.entrypoint.ClusterEntrypointUtils;
import org.apache.flink.runtime.jobgraph.SavepointRestoreSettings;
import org.apache.flink.runtime.resourcemanager.StandaloneResourceManagerFactory;
import org.apache.flink.runtime.util.EnvironmentInformation;
import org.apache.flink.runtime.util.JvmShutdownSafeguard;
import org.apache.flink.runtime.util.SignalHandler;
import org.apache.flink.util.FlinkException;

import javax.annotation.Nullable;

import java.io.File;
import java.io.IOException;

/**
 * An {@link ApplicationClusterEntryPoint} which is started with a job in a predefined
 * location.
 */
@Internal
public final class StandaloneApplicationClusterEntryPoint extends ApplicationClusterEntryPoint {

	private StandaloneApplicationClusterEntryPoint(
			final Configuration configuration,
			final PackagedProgram program) {
		super(configuration, program, StandaloneResourceManagerFactory.getInstance());
	}

	public static void main(String[] args) {
		// startup checks and logging
		EnvironmentInformation.logEnvironmentInfo(LOG, StandaloneApplicationClusterEntryPoint.class.getSimpleName(), args);
		SignalHandler.register(LOG);
		JvmShutdownSafeguard.installAsShutdownHook(LOG);

		final StandaloneApplicationClusterConfiguration clusterConfiguration = ClusterEntrypointUtils.parseParametersOrExit(
			args,
			new StandaloneApplicationClusterConfigurationParserFactory(),
			StandaloneApplicationClusterEntryPoint.class);

		PackagedProgram program = null;
		try {
			program = getPackagedProgram(clusterConfiguration);
		} catch (Exception e) {
			LOG.error("Could not create application program.", e);
			System.exit(1);
		}

		Configuration configuration = loadConfigurationFromClusterConfig(clusterConfiguration);
		try {
			configureExecution(configuration, program);
		} catch (Exception e) {
			LOG.error("Could not apply application configuration.", e);
			System.exit(1);
		}

		StandaloneApplicationClusterEntryPoint entrypoint = new StandaloneApplicationClusterEntryPoint(configuration, program);

		ClusterEntrypoint.runClusterEntrypoint(entrypoint);
	}

	@VisibleForTesting
	static Configuration loadConfigurationFromClusterConfig(StandaloneApplicationClusterConfiguration clusterConfiguration) {
		Configuration configuration = loadConfiguration(clusterConfiguration);
		setStaticJobId(clusterConfiguration, configuration);
		SavepointRestoreSettings.toConfiguration(clusterConfiguration.getSavepointRestoreSettings(), configuration);
		return configuration;
	}

	private static PackagedProgram getPackagedProgram(
			final StandaloneApplicationClusterConfiguration clusterConfiguration) throws IOException, FlinkException {
		final PackagedProgramRetriever programRetriever = getPackagedProgramRetriever(
				clusterConfiguration.getArgs(),
				clusterConfiguration.getJobClassName());
		return programRetriever.getPackagedProgram();
	}

	private static PackagedProgramRetriever getPackagedProgramRetriever(
			final String[] programArguments,
			@Nullable final String jobClassName) throws IOException {
		final File userLibDir = ClusterEntrypointUtils.tryFindUserLibDirectory().orElse(null);
		final ClassPathPackagedProgramRetriever.Builder retrieverBuilder =
				ClassPathPackagedProgramRetriever
						.newBuilder(programArguments)
						.setUserLibDirectory(userLibDir)
						.setJobClassName(jobClassName);
		return retrieverBuilder.build();
	}

	private static void setStaticJobId(StandaloneApplicationClusterConfiguration clusterConfiguration, Configuration configuration) {
		final JobID jobId = clusterConfiguration.getJobId();
		if (jobId != null) {
			configuration.set(PipelineOptionsInternal.PIPELINE_FIXED_JOB_ID, jobId.toHexString());
		}
	}
}
